The present disclosure relates generally to the field of weather display systems. More particularly, the present disclosure relates to a weather display system and method configured to display weather which is obscured by path attenuation.
Weather display systems are often used to alert operators of vehicles, such as aircraft pilots, of weather hazards in the area near the vehicle. Conventional weather display systems are configured to display weather data in two dimensions and often operate according to ARINC 453 and 708 standards. A horizontal plan view provides an overview of weather patterns near an aircraft mapped onto a horizontal plane. Generally the horizontal plan view provides indications of precipitation rates in the vicinity of the aircraft (images of weather). Red, yellow, and green colors are used to symbolize areas of respective precipitation rates, and black color symbolizes areas of very little or no precipitation. Each color is associated with radar reflectivity range which corresponds to a respective precipitation rate range. Red indicates the highest rates of precipitation while green represents the lowest (non-zero) rates of precipitation. Certain displays can also utilize a magenta color to indicate regions of turbulence.
Onboard avionic weather radar systems (e.g., x-band weather radar systems) cannot always penetrate or sense areas beyond intense precipitation or rainfall. Accordingly, cells (e.g. storms) behind a nearby line of cells may be shadowed by the closer cells. This shadowing by the closer cells can deprive the pilot of a view of the complete weather situation through which the aircraft is flying. Conventional avionic weather radar systems such as the WX2100 weather radar manufactured by Rockwell Collins, Inc. can execute a path attenuation compensation (PAC) algorithm that flags any radial where the radar return is too badly attenuated to be corrected. Path attenuation is described in U.S. Pat. No. 5,047,775 incorporated herein by reference
Conventional displays can mark such radials with a yellow bar and/or provide the text “PAC Alert” so that the pilot can be aware that hidden weather may be behind displayed weather cells. However, such systems do not provide an indication of whether or not weather actually exists behind the weather cell or what type of weather exists behind a weather cell.
Thus, there is a need for a weather information display that provides more information than a conventional display. Further, there is a need for a threat depiction system and method that can augment the display of information when weather detection is obscured by path attenuation. Further still, there is a need for an avionic weather system including a path attenuation algorithm that provides an indication of weather beyond the attenuating cell. Yet further, there is a need for a system and method that displays weather despite path attenuation issues. Yet further, there is a need for a weather display that can display weather images using merged data from two different sources.